1. Field of the Invention
The present invention relates to infrared laser light source spreaders, and more particularly, to an infrared laser light source spreader that uses two biconvex lenses, a convex-concave lens, and a biconcave lens.
2. Description of the Prior Art
With the growth of technology adoption, and particularly the development of improved video display and video recording technologies, video surveillance systems are becoming ever more popular. Many businesses and residences today use video surveillance apparatuses to prevent theft and vandalism, or to aid law enforcement in related investigations/prosecutions. The video surveillance system typically includes a video camera, a video recording apparatus, and a video display.
Normal video cameras traditionally are designed to perform well under daylight conditions. Most acts of theft and vandalism occur at night, as fewer people are outside, and darkness provides a measure of cover from the naked eye. This means that the video camera must also perform well at night. To capture video at night, when visible light is greatly reduced, or in other low-light environments where visible light is unavailable, the video cameras typically employ light emitting diodes (LED) to provide a supplemental light source for the video camera. Because the LED is a scattering light source, a visible range of the video camera is severely limited. The prior art typically provides a visible range of about 50 m, and a longest range provided by the prior art is approximately 150 m. For some applications, this range is insufficient.